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awesome-cheatsheets/backend/moleculer.js
2018-03-10 17:11:24 -08:00

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/* *******************************************************************************************
* MOLECULER MICROSERVICES FRAMEWORK - CORE CHEATSHEET
* http://moleculer.services/0.12/docs/
*
* Version: 0.12.x
* ******************************************************************************************* */
/* *******************************************************************************************
* Install Moleculer
* ******************************************************************************************* */
```bash
npm i moleculer
```
/* *******************************************************************************************
* SERVICE BROKER OPTIONS
* ******************************************************************************************* */
// All ServiceBroker options with default values
const broker = new ServiceBroker({
namespace: "", // Namespace for node segmentation
nodeID: null, // NodeID. Default value is generated from hostname and PID
logger: null, // Logger instance.
logLevel: null, // Log level
logFormatter: "default", // Log formatter. Options: "default", "simple"
transporter: null, // Transporter config
requestTimeout: 0 * 1000, // Timeout of requests
requestRetry: 0, // Retries for requests
maxCallLevel: 0, // Maximum calling level.
heartbeatInterval: 5, // Heartbeat sending interval in seconds
heartbeatTimeout: 15, // Heartbeat timeout in seconds
disableBalancer: false, // Disable the built-in Moleculer balancer
registry: { // Service Registry options
strategy: "RoundRobin", // Invocation strategy
strategyOptions: null, // Strategy options
preferLocal: true // Prefer local invocations
},
circuitBreaker: { // Circuit-breaker options
enabled: false, // Enable circuit-breaker
maxFailures: 3, // Maximum failures
halfOpenTime: 10 * 1000, // Half-open time interval
failureOnTimeout: true, // Failure on timeouts
failureOnReject: true // Failure on rejects
},
transit: { // Transit options
maxQueueSize: 50 * 1000 // Max items in outgoing queue
},
cacher: null, // Cacher config
serializer: null, // Serializer config
validation: true, // Enable params validation
validator: null, // Validator instance
metrics: false, // Enable metrics
metricsRate: 1, // Metrics rate
statistics: false, // Enable statistics
internalServices: true, // Load internal ($node) services
hotReload: false, // Hot-reload services
middlewares: null, // List of middlewares
replCommands: null, // Custom REPL commands
ServiceFactory: null, // Custom Service factory class
ContextFactory: null // Custom Context factory class
});
/* *******************************************************************************************
* SERVICE BROKER METHODS
* ******************************************************************************************* */
// Broker properties
broker.Promise // Pointer to Bluebird Promise lib
broker.namespace // Namespace from options
broker.nodeID // Local NodeID
broker.logger // Logger instance
broker.cacher // Cacher instance
broker.serializer // Serializer instance
broker.validator // Validator instance
// Broker methods
broker.start(); // Start broker & all services. Returns a Promise
broker.stop(); // Stop broker & all services. Returns a Promise
broker.fatal(message, err, needExit = true); // Fired a fatal error.
broker.repl(); // Switch broker to REPL mode.
broker.getLogger(module, service, version); // Create a custom logger instance for modules
broker.loadServices(folder, fileMask); // Load all services from directory
broker.loadService(filePath); // Load a service from a file
broker.createService(schema, schemaMods); // Create a local service from schema
broker.destroyService(service); // Destroy a local service
broker.getLocalService(name, version); // Get a local service instance by name
// Wait for services. Returns a Promise
await broker.waitForServices(serviceNames, timeout, interval);
await broker.waitForServices(["posts", "users"], 5000);
await broker.waitForServices({
name: "posts", version: 2,
name: "users", version: 1
}, 5000);
broker.use(...middlewares); // Register middlewares
broker.call(actionName, params, opts); // Call a service
broker.mcall(def); // Multiple service calls
broker.emit(eventName, payload, groups); // Emit a balanced event
broker.broadcast(eventName, payload, groups = null) // Broadcast an event
broker.broadcastLocal(eventName, payload, groups = null) // Broadcast an event to local services
broker.sendPing(nodeID); // Ping a remote node
broker.MOLECULER_VERSION // Version number of Moleculer lib
broker.PROTOCOL_VERSION // Version number of Moleculer protocol
/* *******************************************************************************************
* BROKER SERVICE CALLS
* ******************************************************************************************* */
// Call the "users.get" service with params
broker.call("users.get", { id: 150 }).then(user => console.log(user));
// Call with async/await
const user = await broker.call("users.get", { id: 150});
// Call with calling options
const user = await broker.call("users.get", { id: 150}, { timeout: 5000, retryCount: 3 });
// Direct call to a remote node
const info = await broker.call("$node.services", null, { nodeID: "node-123" });
// Multiple calls with array def
const [posts, users] = await broker.mcall([
{ action: "posts.find", params: { limit: 5, offset: 0 } },
{ action: "users.find", params: { limit: 5, sort: "username" }, opts: { timeout: 500 } }
]);
// Multip calls with object def
const res = await broker.mcall({
posts: { action: "posts.find", params: { limit: 5, offset: 0 } },
users: { action: "users.find", params: { limit: 5, sort: "username" }, opts: { timeout: 500 } }
});
console.log(res.posts, res.users);
/* *******************************************************************************************
* BROKER EVENTS
* ******************************************************************************************* */
// Send a balanced event with payload
broker.emit("user.created", { user: user });
// Send a balanced event only for "mail" and "payment" service (only one instance)
broker.emit("user.created", { user: user }, ["mail", "payment"]);
// Send a broadcast event (for all service instances)
broker.broadcast("user.created", { user: user });
// Send a broadcast event only for "mail" and "payment" services (all instances)
broker.broadcast("user.created", { user: user }, ["mail", "payment"]);
/* *******************************************************************************************
* NATS TRANSPORTER
* Requirement: `npm i nats`
* ******************************************************************************************* */
// Default options
const broker = new ServiceBroker({
transporter: "NATS"
});
// With URI
const broker = new ServiceBroker({
transporter: "nats://localhost:4222"
});
// With options
const broker = new ServiceBroker({
transporter: {
type: "NATS",
options: {
url: "nats://localhost:4222",
user: "admin",
pass: "1234"
}
}
});
// With TLS (https://github.com/nats-io/node-nats#tls)
const broker = new ServiceBroker({
transporter: {
type: "NATS",
options: {
url: "nats://localhost:4222",
tls: {
key: fs.readFileSync('./client-key.pem'),
cert: fs.readFileSync('./client-cert.pem'),
ca: [ fs.readFileSync('./ca.pem') ]
}
}
}
});
/* *******************************************************************************************
* REDIS TRANSPORTER
* Requirement: `npm i ioredis`
* ******************************************************************************************* */
// Default options
const broker = new ServiceBroker({
transporter: "Redis"
});
// With URI
const broker = new ServiceBroker({
transporter: "redis://redis-server:6379"
});
// With options
const broker = new ServiceBroker({
transporter: {
type: "Redis",
options: {
port: 6379, // Redis port
host: 'redis-server', // Redis host
family: 4, // 4 (IPv4) or 6 (IPv6)
password: 'auth', // Password
db: 0 // Database index
}
}
});
/* *******************************************************************************************
* MQTT TRANSPORTER
* Requirement: `npm i mqtt`
* ******************************************************************************************* */
// Default options
const broker = new ServiceBroker({
transporter: "MQTT"
});
// With URI
const broker = new ServiceBroker({
transporter: "mqtt://mqtt-server:1883"
});
// With options
const broker = new ServiceBroker({
transporter: {
type: "MQTT",
options: {
host: "mqtt-server",
port: 1883,
username: "admin",
password: "1234"
}
}
});
/* *******************************************************************************************
* AMQP TRANSPORTER
* Requirement: `npm i amqplib`
* ******************************************************************************************* */
// Default options
const broker = new ServiceBroker({
transporter: "AMQP"
});
// With URI
const broker = new ServiceBroker({
transporter: "amqp://rabbitmq-server:5672"
});
// With options
const broker = new ServiceBroker({
transporter: {
type: "AMQP",
options: {
url: "amqp://user:pass@rabbitmq-server:5672",
eventTimeToLive: 5000,
prefetch: 1
}
}
});
/* *******************************************************************************************
* KAFKA TRANSPORTER
* Requirement: `npm i kafka-node`
* ******************************************************************************************* */
// Default options
const broker = new ServiceBroker({
transporter: "Kafka"
});
// With URI
const broker = new ServiceBroker({
transporter: "kafka://192.168.51.29:2181"
});
// With options
const broker = new ServiceBroker({
transporter: {
type: "kafka",
options: {
host: "192.168.51.29:2181",
// KafkaClient options. More info: https://github.com/SOHU-Co/kafka-node#clientconnectionstring-clientid-zkoptions-noackbatchoptions-ssloptions
client: {
zkOptions: undefined,
noAckBatchOptions: undefined,
sslOptions: undefined
},
// KafkaProducer options. More info: https://github.com/SOHU-Co/kafka-node#producerclient-options-custompartitioner
producer: {},
customPartitioner: undefined,
// ConsumerGroup options. More info: https://github.com/SOHU-Co/kafka-node#consumergroupoptions-topics
consumer: {
},
// Advanced options for `send`. More info: https://github.com/SOHU-Co/kafka-node#sendpayloads-cb
publish: {
partition: 0,
attributes: 0
}
}
}
});
/* *******************************************************************************************
* NATS STREAMING TRANSPORTER
* Requirement: `npm i node-nats-streaming`
* ******************************************************************************************* */
// Default options
const broker = new ServiceBroker({
transporter: "STAN"
});
// With URI
const broker = new ServiceBroker({
transporter: "stan://192.168.0.120:4222"
});
// With options
const broker = new ServiceBroker({
transporter: {
type: "STAN",
options: {
url: "stan://127.0.0.1:4222",
clusterID: "my-cluster"
}
}
});
/* *******************************************************************************************
* TCP STREAMING TRANSPORTER
* No requirements
* ******************************************************************************************* */
// Default options
const broker = new ServiceBroker({
transporter: "TCP"
});
// With static node list
const broker = new ServiceBroker({
transporter: "tcp://172.17.0.1:6000/node-1,172.17.0.2:6000/node-2"
});
const broker = new ServiceBroker({
nodeID: "node-1",
transporter: {
type: "TCP",
options: {
udpDiscovery: false,
urls: [
"172.17.0.1:6000/node-1",
"172.17.0.2:6000/node-2",
"172.17.0.3:6000/node-3"
]
}
}
});
// With full options
const broker = new ServiceBroker({
logger: true,
transporter: {
type: "TCP",
options: {
// Enable UDP discovery
udpDiscovery: true,
// Reusing UDP server socket
udpReuseAddr: true,
// UDP port
udpPort: 4445,
// UDP bind address
udpBindAddress: null,
// UDP sending period
udpPeriod: 5,
// Multicast address.
udpMulticast: "239.0.0.0",
// Multicast TTL setting
udpMulticastTTL: 1,
// Send broadcast
udpBroadcast: false,
// TCP server port. Null or 0 means random port
port: null,
// Static remote nodes address list (when UDP discovery is not available)
urls: null,
// Use hostname as preffered connection address
useHostname: true,
// Gossip sending period in seconds
gossipPeriod: 2,
// Maximum enabled outgoing connections. If reach, close the old connections
maxConnections: 32,
// Maximum TCP packet size
maxPacketSize: 1 * 1024 * 1024
}
}
});
/* *******************************************************************************************
* CACHERS
* http://moleculer.services/docs/cachers.html
* ******************************************************************************************* */
// Memory cacher
const broker = new ServiceBroker({
cacher: "Memory"
});
// or
const broker = new ServiceBroker({
cacher: true
});
// Memory cacher with options
const broker = new ServiceBroker({
cacher: {
type: "Memory",
options: {
ttl: 30
}
}
});
// Redis cacher
const broker = new ServiceBroker({
cacher: "Redis"
});
// Redis cacher with URI
const broker = new ServiceBroker({
cacher: "redis://redis-server:6379"
});
// Redis cacher with options
const broker = new ServiceBroker({
cacher: {
type: "Redis",
options: {
prefix: "MOL",
redis: {
host: "redis",
port: 6379,
password: "1234",
db: 0
}
}
}
});
/* *******************************************************************************************
* Manual caching
* ******************************************************************************************* */
// Save to cache
broker.cacher.set("mykey.a", { a: 5 });
// Get from cache
const obj = await broker.cacher.get("mykey.a");
// Remove entry from cache
broker.cacher.del("mykey.a");
// Clean all 'mykey' entries
broker.cacher.clean("mykey.*");
// Clean all entries
broker.cacher.clean();
/* *******************************************************************************************
* SERIALIZER
* http://moleculer.services/docs/serializers.html
* ******************************************************************************************* */
// JSON serializer (default)
const broker = new ServiceBroker({
serializer: "JSON"
});
// Avro serializer (need `npm i avsc`)
const broker = new ServiceBroker({
serializer: "Avro"
});
// Protocol Buffer serializer (need `npm i protobufjs`)
const broker = new ServiceBroker({
serializer: "ProtoBuf"
});
// MsgPack serializer (need `npm i msgpack5`)
const broker = new ServiceBroker({
serializer: "MsgPack"
});
/* *******************************************************************************************
* STRATEGY
* ******************************************************************************************* */
// Round-robin strategy (default)
const broker = new ServiceBroker({
registry: {
strategy: "RoundRobin"
}
});
// Random strategy
const broker = new ServiceBroker({
registry: {
strategy: "Random"
}
});
// CPU usage-based strategy
const broker = new ServiceBroker({
registry: {
strategy: "CpuUsageStrategy"
}
});
// CPU usage-based strategy with options
const broker = new ServiceBroker({
registry: {
strategy: "CpuUsageStrategy",
strategyOptions: {
sampleCount: 3,
lowCpuUsage: 10
}
}
});
/* *******************************************************************************************
* LOGGER
* http://moleculer.services/docs/logger.html
* ******************************************************************************************* */
// Logger methods
broker.logger.fatal();
broker.logger.error();
broker.logger.warn();
broker.logger.info();
broker.logger.debug();
broker.logger.trace();
// Custom log formatter
const broker = new ServiceBroker({
logger: console,
logFormatter(level, args, bindings) {
return level.toUpperCase() + " " + bindings.nodeID + ": " + args.join(" ");
}
});
// External Pino logger
const pino = require("pino")({ level: "info" });
const broker = new ServiceBroker({
logger: bindings => pino.child(bindings)
});
// External Bunyan logger
const logger = require("bunyan").createLogger({ name: "moleculer", level: "info" });
const broker = new ServiceBroker({
logger: bindings => logger.child(bindings)
});
/* *******************************************************************************************
* SERVICE SCHEMA
* ******************************************************************************************* */
module.exports = {
// Name
name: "greeter",
// Version
version: 2,
// Settings
settings: {},
// Metadata
metadata: {},
// Dependencies
dependencies: [],
// Actions
actions: {
// Shorthand actions
hello() {
// Call a method
this.doSomething();
return "Hello Moleculer";
},
// With properties
welcome: {
// Cache options
cache: {
keys: ["name"]
},
// Validation options
params: {
name: "string"
},
// Action handler
handler(ctx) {
return `Welcome, ${ctx.params.name}`;
}
}
},
events: {
"user.created"(payload, sender) {
}
},
// Service methods
methods: {
doSomething() {}
},
// Lifecycle event handlers
created() {
console.log("Service created");
},
started() {
console.log("Service started");
return Promise.resolve();
},
stopped() {
console.log("Service stopped");
return Promise.resolve();
}
};
/* *******************************************************************************************
* SERVICE
* ******************************************************************************************* */
this.name // Name of service
this.version // Version of service
this.settings // Settings of service
this.schema // Schema definition of service
this.broker // Broker instance
this.Promise // Class of Promise (Bluebird)
this.logger // Logger instance
this.actions // Actions of service.
this.waitForServices // Pointer to broker.waitForServices method
/* *******************************************************************************************
* CONTEXT
* ******************************************************************************************* */
ctx.id // Context ID
ctx.broker // Broker instance
ctx.action // Action definition
ctx.nodeID // Node ID
ctx.requestID // Request ID
ctx.parentID // ID of parent context (in case of sub-calls).
ctx.params // Request params
ctx.meta // Request metadata
ctx.callerNodeID // Caller Node ID if it is requested from a remote node.
ctx.level // Request level (in case of sub-calls). The first level is 1.
// Make a sub-call
ctx.call(actionName, params, callingOptions)
// Emit an event
ctx.emit(eventName, payload, groups);